Electrical cables which are used for supplying electrical energy to, for example, submersible oil well pumps are exposed to significant mechanical stresses and therefore are advantageously covered with an armored jacket. In addition, it is highly advantageous to protect the electrical conductors inside the jacket with a plurality of force-resisting members to specifically resist transverse compression of the cable.
An example of such cable is disclosed in U.S. Pat. No. 4,409,431, the disclosure of which is hereby incorporated by reference and includes three side-by-side conductors with a force-resisting member located between adjacent conductors, thereby forming a flat cable. Another example of such cable is disclosed in prior filed, commonly owned U.S. Pat. No. 4,454,378, the disclosure of which is hereby incorporated by reference and includes a similar structure shown in U.S. Pat. No. 4,409,431 but with an arcuate cross section. A third example of such cable is disclosed in prior filed, commonly owned U.S. Pat. No. 4,454,377, the disclosure of which is hereby incorporated by reference and includes a plurality of force-resisting U-shaped channel members having lead liners therein, these members being located between adjacent conductors.
The structures shown in that patent and applications have been additionally improved upon by providing force-resisting members on the outer edges of the cable to provide the cable with an essentially rectangular cross section.
As is evident, the automatic fabrication of such electrical cables is quite challenging since these cables are typically 8,000 to 10,000 feet long and a plurality of electrical conductors and a plurality of the force-resisting members must be correctly combined and then the armored jacket must be applied around the combination. Complicating this fabrication is the special cross-sectional configuration of each force-resisting member which must be specifically oriented and aligned relative to the conductors and the other force-resisting members. While construction of armored electrical cable has been known in the past, the apparatus and methods which are conventionally practiced deal mainly with a single conductor or a cable having a circular or oval cross section, which are fairly simple to construct and whose parts do not require specific orientation and alignment.
Accordingly, there is a specific need to provide an improved apparatus and method for making armored electrical cable that is constructed of a plurality of conductors and force-resisting members with a rectangular cross section.